how is this not a draw at the end i should not have lost because of time

here is the game two bishops of opposite color and two kings no pawns how is it not a draw lichess.org/3NCzswGqxnOK

You can still get checkmated like this:

It has happened before I watched an NM do it on stream once in a bullet game, after his selfmate he almost threw the keyboard.

FIDE rules, F.A.Q.

If you don’t know now you know.